Steve Blackmore wrote: > > I've no idea how, or if it's possible to average the encoder readout? > > The pastebin you showed indicated it is missing counts. You say scope traces indicate the encoder is working OK. So, it has something to do with the way the computer is reading the counts. Averaging will only make a mess, if the original counts are being dropped here and there. I do not think, based on the pastebin, that it is a sampling rate problem, due to the large variance in the numbers. (I'm still not real clear on what those numbers were, but they were quite consistent for a long run, then suddenly there was a number with 50 - 100% variation! If the numbers were all +/- 10%, averaging might help.
I usually figure that you need a sampling rate at least 3 times the actual count rate, to take care of the situations where the phase angle between the two channels isn't quite 90 degrees, the duty cycles of the pulses are not quite 50% and all that hits right at the worst interval between samples. So, I rate my UPC and USC boards for 300 KHz encoder count rate, while they are actually sampled at 1 MHz. I have my own digital filter circuit that is designed to eliminate false quadrature transitions, and part of that is limiting the sampling rate. You have probably already given this info, but what is the max encoder count rate, and what is the sampling rate (I assume BASE_THREAD)? Jon ------------------------------------------------------------------------------ Come build with us! The BlackBerry® Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9-12, 2009. Register now! http://p.sf.net/sfu/devconf _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
